In the field of airframe assembly, there is an ongoing effort to provide for a reliable, efficient and economical way to manually drill a hole perpendicular to the surface of a complex airframe assembly.
Manual drilling of complex exterior airframe assemblies and parts account for approximately 40 percent of required drilling at the airframe assembly level. Airframe assemblies and parts are generally received with pre-drilled target holes (e.g., determinant assembly holes). A machinist may be required to enlarge the target hole to accommodate, for example, the addition of components or to attach adjoining assemblies. A machinist may be required to drill a hole substantially perpendicular to the surface of the assembly at the location of the target hole. Assemblies may include multiple layers of structural materials in varying hardness and quality and such assemblies may range from approximately ¾ inch to 1½ inches in overall thickness. Some assemblies may be contoured and have irregular shapes and/or curvatures in multiple directions. For example, the first component in a multi-layered assembly may be a composite barrel of ever changing conic shape. Additional layers of an assembly may be expensive materials such as forged titanium or forged aluminum.
Conventional manual hand drilling systems employ a number of techniques to drill a hole perpendicular to a contoured composite surface. However, these conventional systems typically lack the necessary features required to reliably guide a drill bit perpendicular to a surface over the multitude of complex airframe assembly contoured surfaces. An eggcup tool may be used as a hand-held drill guide to guide a drill bit substantially perpendicular to a non-planar work surface. Unfortunately, eggcup tools rely on the work surface to be substantially flat to achieve a drilled hole perpendicular to the work surface.
Custom drill blocks may be used as a drill guide for manual drilling applications where the surface to be drilled includes multiple contours, curvatures and/or obstructions. However, a custom drill block may be extremely complex and costly to both design and manufacture. Further, multiple custom drill blocks may be required as their use is limited to specific surface contours and assembly locations.
As set forth above, these approaches fail to provide for a reliable, adaptable and economical manual hand drill system. Thus, there is a need to provide a reliable and adaptable apparatus and efficient and repeatable method to accurately drill a hole substantially perpendicular to a surface of a complex airframe assembly or component.